Clinical and molecular characteristics of RNF43 mutations as promising prognostic biomarkers in colorectal cancer.

Background: Transmembrane E3 ubiquitin ligase (RNF43) mutations are present in approximately 6-18% of colorectal cancers (CRC) and could enhance Wnt/ß-catenin signaling, which is emerging as a promising therapeutic target. This study aims to investigate the clinical and molecular characteristics and potential heterogeneity of RNF43-mutant CRC. Methods: A total of 78 patients with RNF43-mutant CRC were enrolled from July 2013 to November 2022. Demographic data, clinical characteristics, treatment regimens used, and survival outcomes were collected and analyzed. Results: Our study uncovered that patients with RNF43 mutations in the N-terminal domain (NTD; n = 50) exhibited shorter overall survival (OS; median months, 50.80 versus not reached; p = 0.043) compared to those in the C-terminal domain (CTD; n = 17). Most RNF43 mutations in NTD had positive primary lymph node status, low tumor mutation burden (TMB-L), and correlated with proficient mismatch repair (pMMR)/microsatellite stable (MSS) status. By contrast, RNF43 mutations in CTD were significantly enriched in deficient MMR (dMMR)/microsatellite instability (MSI-H) tumors with high TMB (TMB-H). N-terminal RNF43-mutated tumors harbored a hotspot variant (RNF43 R117fs), which independently predicted a significantly worse outcome in pMMR/MSS CRC with a median OS of 18.9 months. Patients with RNF43 mutations and the BRAF V600E alterations demonstrated sensitivity to BRAF/EGFR inhibitors. Moreover, we observed that pMMR/MSS patients with RNF43 R117fs mutation had a higher incidence of stage IV, ⩾2 metastatic sites, low TMB, and none of them received PD-1/PD-L1 inhibitor therapy. Conclusion: Our findings provide the first evidence that RNF43 mutations in NTD and the R117fs variant correlate with a poorer prognosis in CRC patients, providing strategies for Wnt-targeted therapy to improve clinical efficacy.

Monitoring tumour resistance to the BRAF inhibitor combination regimen in colorectal cancer patients via circulating tumour DNA.

AIMS: This study aimed to identify mechanisms of drug resistance to the combination of vemurafenib, irinotecan, and cetuximab (VIC) in BRAFV600E metastatic colorectal cancer (mCRC). METHODS: Forty-one patients with BRAFV600E mCRC from July 2018 and June 2020 were evaluated, with tissue and/or plasma samples collected. We profiled tissue and plasma samples using whole-exome sequencing and targeted sequencing of 425 cancer-relevant genes. Clinical cohort analysis from published studies was performed to consolidate our findings. RESULTS: BRAF mutant in baseline plasma and its dynamics are significantly associated with VIC-related response, and concurrent RNF43 mutation significantly sensitises tumour to VIC treatment. VIC resistance frequently involves genes in PI3K, MAPK pathway, and several novel resistance mechanisms such as TGFBR2 and SMAD4 mutations, and copy-number gains in PTK2, MYC, and GATA6 have been identified. We also firstly describe acquired altered genes in DNA damaging repair pathway, occurring in 33 % of patients after VIC treatment, and particularly, patients with this pre-treatment resistance subclones developed inferior responses, along with higher tumour mutation burden both at baseline and progression plasma. CONCLUSION: Analysis of ctDNA can provide novel insights into molecular resistance mechanisms to VIC in BRAFV600E mCRC patients, allowing accurate guidance for clinicians in personalised treatment strategies.

Heterogeneity and evolution of tumour immune microenvironment in metastatic gastroesophageal adenocarcinoma.

BACKGROUND: Tumour immune microenvironment heterogeneity is prevalent in numerous cancers and can negatively impact immunotherapy response. Immune heterogeneity and evolution in gastroesophageal adenocarcinoma (GEA) have not been studied in the past. METHODS: Together with a multi-region sampling of normal, primary and metastatic tissues, we performed whole exome sequencing, TCR sequencing as well as immune cell infiltration estimation through deconvolution of gene expression signals. RESULTS: We discovered high TCR repertoire and immune cell infiltration heterogeneity among metastatic sites, while they were homogeneous among primary and normal samples. Metastatic sites shared high levels of abundant TCR clonotypes with blood, indicating immune surveillance via blood. Metastatic sites also had low levels of tumour-eliminating immune cells and were undergoing heavy immunomodulation compared to normal and primary tumour tissues. There was co-evolution of neo-antigen and TCR repertoire, but only in patients with late diverging mutational evolution. Co-evolution of TCR repertoire and immune cell infiltration was seen in all except one patient. CONCLUSIONS: Our findings revealed immune heterogeneity and co-evolution in GEA, which may inform immunotherapy decision-making.

Circulating Lipid- and Inflammation-Based Risk (CLIR) Score: A Promising New Model for Predicting Outcomes in Complete Colorectal Liver Metastases Resection.

BACKGROUND: Colorectal cancer liver metastasis (CRLM) is a determining factor affecting the survival of colorectal cancer (CRC) patients. This study aims at developing a novel prognostic stratification tool for CRLM resection. METHODS: In this retrospective study, 666 CRC patients who underwent complete CRLM resection from two Chinese medical institutions between 2001 and 2016 were classified into the training (341 patients) and validation (325 patients) cohorts. The primary endpoint was overall survival (OS). Associations between clinicopathological variables, circulating lipid and inflammation biomarkers, and OS were explored. The five most significant prognostic factors were incorporated into the Circulating Lipid- and Inflammation-based Risk (CLIR) score. The predictive ability of the CLIR score and Fong's Clinical Risk Score (CRS) was compared by time-dependent receiver operating characteristic (ROC) analysis. RESULTS: Five independent predictors associated with worse OS were identified in the training cohort: number of CRLMs >4, maximum diameter of CRLM >4.4 cm, primary lymph node-positive, serum lactate dehydrogenase (LDH) level >250.5 U/L, and serum low-density lipoprotein-cholesterol (LDL-C)/high-density lipoprotein-cholesterol (HDL-C) ratio >2.9. These predictors were included in the CLIR score and each factor was assigned one point. Median OS for the low (score 0-1)-, intermediate (score 2-3)-, and high (score 4-5)-risk groups was 134.0 months, 39.9 months, and 18.7 months in the pooled cohort. The CLIR score outperformed the Fong score with superior discriminatory capacities for OS and RFS, both in the training and validation cohorts. CONCLUSIONS: The CLIR score demonstrated a promising ability to predict the long-term survival of CRC patients after complete hepatic resection.

The Prognostic Value of Locoregional Interventions for BRAF V600E Metastatic Colorectal Cancer: A Retrospective Cohort Analysis.

The prognostic heterogeneity in patients with BRAF V600E metastatic colorectal cancer (mCRC) remains poorly defined. Real-world data of 93 BRAF V600E mCRC patients from Sun Yat-sen University Cancer Center were evaluated using the prognostic factors affecting overall survival (OS). Treatment of metastases served as an independent prognosticator, where curative locoregional interventions (LRIs) were associated with superior clinical outcomes (adjusted hazard ratio (HR): 0.46, 95% confidence interval (CI): 0.22-0.98; p = 0.044). The LRIs group showed an improved median OS of 49.4 months versus 18.3 months for the palliative treatments (PTs) group. The median OS of patients with colorectal liver metastasis (CRLM) was significantly prolonged after undergoing LRIs (42.4 vs. 23.7 months; HR: 0.11, 95% CI: 0.01-1.22; p = 0.030), and patients in the LRIs plus liver-limited or lung-limited metastasis (LLM) group benefited more than those in the LRIs plus non-LLM group when compared to the PTs group (LLM from LRIs vs. PTs, HR: 0.16, 95% CI: 0.04-0.68; p = 0.006. Non-LLM from LRIs vs. PTs, HR: 0.47, 95% CI: 0.21-1.05; p = 0.074). In conclusion, we confirmed the positive prognostic value of LRIs in BRAF V600E mCRC, particularly in patients with CRLM or LLM.

Efficacy and safety of modified FOLFIRINOX as salvage therapy for patients with refractory advanced biliary tract cancer: a retrospective study.

Background Gemcitabine plus cisplatin is regarded as the standard first-line therapy for patients with advanced biliary tract cancer (BTC); however, no standard chemotherapy has yet been recommended after treatment failure. Modified FOLFIRINOX (mFOLFIRINOX) appears to be a better-tolerated regimen, which leads to improved survival in metastatic pancreatic cancer that has histological and molecular similarities with BTC. We assessed the efficacy and safety of mFOLFIRINOX as salvage therapy in advanced BTC patients who were refractory to previous chemotherapy. Methods A total of 15 consecutive patients with documented unresectable locally advanced or metastatic BCT who received the mFOLFIRINOX regimen were included in the study. Patients were intravenously administrated with oxaliplatin (65 mg/m2), leucovorin (400 mg/m2), irinotecan (150 mg/m2), and continuous infusion of fluorouracil (2400 mg/m2) over 46 h. The objective response rates (ORR), disease control rates (DCR), progression-free survival (PFS), overall survival (OS), and adverse events (AEs) were recorded. Results At least three cycles of mFOLFIRINOX regimen were delivered to 15 patients with a median number of 6.0 cycles (IQR 5.5-11.0). The median duration of treatment was 3.8 months (IQR 2.9-8.5). Four patients (26.7%) achieved an ORR, and 12 patients (80.0%) had a DCR. The median PFS and OS were 6.7 months (95%CI 2.3-11.1) and 13.2 months (95%CI 7.3-19.1), respectively. Five patients (33.3%) had treatment-related grade 3/4 AEs. The most common grade 3/4 AE was neutropenia (n = 3, 20.0%), while there was no occurrence of febrile neutropenia. Conclusion Treatment with mFOLFIRINOX has promising efficacy and favorable tolerance as salvage therapy in patients with refractory advanced BCT.

Baicalin reversal of DNA hypermethylation-associated Klotho suppression ameliorates renal injury in type 1 diabetic mouse model.

Baicalin is a flavone glycoside that possesses numerous pharmacological properties. but its protective mode of action in kidney injury induced by diabetes mellitus remains incompletely understood. Using a streptozotocin (STZ)-induced diabetic mouse model, we found that baicalin could ameliorate diabetes-induced the pathological changes of the kidney function and morphology through suppressing inflammation and oxidative stress. Furthermore, baicalin treatment could alleviate interstitial fibrosis in the diabetic kidney via inhibiting epithelial-to-mesenchymal transition (EMT), which was accompanied by a sharp upregulation of Klotho, the endogenous inhibitor of renal fibrosis. We further verified that baicalin-rescued expression of Klotho was associated with Klotho promoter hypomethylation due to aberrant methyltransferase 3a expressions. Klotho knockdown via RNA interferences largely abrogated the anti-renal fibrotic effects of Baicalin in HK2 cells. These findings suggested that baicalin could alleviate renal injury-induced by diabates through partly modulating Klotho promoter methylation, which provides new insights into the treatment of diabetic nephropathy.